I've lived and experienced traffic all over this country including LA, DC, Chicago, Cleveland, Nashville, Tampa, Miami and find that every metro area is terrible when it comes to traffic, one not being more so than the other because it largely depends on what route you're taking, distance, proximity to freeways, etc.
When it comes to Orlando, if you don't have a car in this town you're screwed, plain and simple. If I were to take the bus to work each day the ride would be 4 hours. You heard that right, 4 hours. It just took me 50 minutes to go 7.4 miles by car.
Jules, the old people in Florida don't live in the urban areas, they live out in little communities by themselves for the most part. Orlando has one single Interstate that runs north/south. This interstate was designed for 20k cars/day - right now it's getting around 625k cars/day. The majority of the road is 3 lane each way with sections of 4 lanes in a few areas. All of the other usefull, dedicated highways are toll roads so your options are take city streets everywhere you go and sit for hours in traffic OR pay up. SR408 runs east/west through town and is the busiest. When I moved to Orlando in 1993 it was just being complete and was 2 lanes each way, now it's 4 lanes each way in most places and still comes to gridlock. SR429 is a newer road which runs north/south on the far west end and is usually flowing ok - it's getting to it that's the problem. SR417 runs north/south on the far east end and typically runs smoothly but again, it's getting two it. The FL Turnpike runs through Orlando with exactly four exits so for the majority of people it's completely useless.
If you asked me a few years ago where I thought the most terrible traffic was I would say Atlanta. Dear god I have wasted a lot of time in Atlanta traffic.